World food production is responsible for a third of all global warming gases emitted by human activity, and the use of animals for meat causes twice as much pollution as food production. plant origin, according to a new important study.
According to research, the entire food production system, such as the use of agricultural machinery, fertilizer spraying and transportation of products, causes 17.3 billion metric tons of greenhouse gases per year. This huge release of gases fueling the climate crisis is more than double all U.S. emissions and accounts for 35 percent of all global emissions, the researchers said.
“The emissions are at the higher end than we expected, it was a bit of a surprise,” said Atul Jain, a climate scientist at the University of Illinois and co-author of the paper, published in Nature Food. “This study shows the whole cycle of the food production system and policymakers may want to use the results to think about how to control greenhouse gas emissions.”
The collection and abandonment of animals for food is much worse for the climate than the cultivation and processing of fruits and vegetables for food, according to research, which confirms previous results on the excessive impact that the production of meat, especially beef, has on the environment.
The research found that the use of cows, pigs and other animals for food, as well as for livestock feed, is responsible for 57% of all food production emissions, with 29% coming from the cultivation of plant-based foods. The rest comes from other land uses, such as for cotton or rubber. Beef accounts for only a quarter of the emissions produced by raising and growing food.
Grazing animals require a lot of land, which is often cleared by deforestation, as well as vast expanses of additional land to cultivate their feed. The paper estimates that most of the world’s farmland is used to feed livestock instead of people. Livestock also produces large amounts of methane, a powerful greenhouse gas.
“All of this combined means emissions are very high,” said Xiaoming Xu, another University of Illinois researcher and lead author of the work. “To produce more meat we need to feed more animals, which generates more emissions. You need more biomass to feed the animals in order to get the same amount of calories. It’s not very efficient. “
The difference in emissions between meat and plant production is clear: to produce 1 kg of wheat, 2.5 kg of greenhouse gases are emitted. Meanwhile, a single kilo of beef generates 70 kg of emissions. The researchers said societies should be aware of this significant discrepancy when tackling the climate crisis.
“I’m a strict vegetarian and part of the motivation for this study was to know my own carbon footprint, but it’s not our intention to force people to change their diet,” Jain said. “Much of this is due to personal choice. You cannot impose your opinion on others. But if people are worried about climate change, they should seriously consider changing their eating habits. “
The researchers built a database that provided a consistent emission profile of 171 crops and 16 animal products, obtaining data from more than 200 countries. They found that South America is the region with the highest proportion of animal food emissions, followed by South and Southeast Asia and then China. Food-related emissions have grown rapidly in China and India, as increasing wealth and cultural changes have led more young people in these countries to adopt meat-based diets.
The document’s calculations on the climate impact of meat are higher than previous estimates: the Food and Agriculture Organization of the United Nations has said that about 14% of emissions come from production. of meat and diets. The climate crisis is also causing famine, with a recent study finding that one-third of world food production would be at risk by the end of the century if greenhouse gas emissions continue to rise at the current rate.
Scientists have consistently stressed that avoiding dangerous global warming requires a major rethinking of eating habits and agricultural practices. Meat production has expanded to the point that there are now about three chickens for every human being on the planet.
Lewis Ziska, a plant physiologist at Columbia University who did not participate in the research, said the document is a “damn good study” that “due attention” should be paid to the upcoming UN climate talks. in Scotland.
“A key unknown in global agriculture is its impact on greenhouse gas emissions,” Ziska said. “Although previous estimates have been made, this effort represents a gold standard that will serve as an essential benchmark in the coming years.”